1. Field of the Invention
The present invention relates generally to a compressor, such as a compressor for an automotive air conditioner system. More particularly, the invention relates to a compressor with means for sealing gas and lubricant.
2. Description of the Background Art
In general, a compressor is filled with a predetermined amount of lubricant for lubrication of rotating and/or thrusting components. The amount of lubricant has to be enough for successfully establishing a lubricating layer between rotating or thrusting component and stationary components even at high load conditions on the compressor. It is also a typical manner of shipping the compressor to fill the compressor with an inert gas, such as a nitrogen gas, for anti-rusting purposes. In order to hold the inert gas and lubricant during transportation, sealing plugs are engaged with the inlet and outlet of the compressor, which inlet and outlet are to be connected a to fluid circuit when it is assembled an to associated unit, such as an automotive air conditioner system.
A typical construction has been disclosed in Japanese Patent First (unexamined) Publication No. 62-135680. In the shown construction, the compressor housing is formed with an inlet and an outlet so that the compressor can be connected to the associated unit, such as the air conditioner system, for introducing low pressure fluid and feeding pressurized fluid for circulating in a fluid circuit. A check valve is provided in the vicinity of the inlet for preventing surge flow of the high pressure fluid. The check valve is maintained at open position while the compressor is driven so that the fluid can be introduced through the inlet. While the compressor in the inoperative state, the check valve is subject to internal pressure of the compressor to be maintained at the closed position.
Upon shipping the individual assembly of the compressor disconnected from the associated unit, the inlet and the outlet are sealed by means of sealing plugs engaged thereto. The compressor is filled with a predetermined amount of lubricant and an inert gas which is filled for anti-rusting purposes. The lubricant is typically filled in the discharge chamber which is provided in fluid communication with the outlet. For completing the anti-rusting purpose the inert gas has to be filled completely by replacing it with an oxygen containing gas, such as an air. Therefore, relatively high pressure of inert gas is required to assure removal of oxygen containing gas.
Upon assembling the compressor with the associated unit by connecting the inlet and outlet to the associated fluid circuit, the sealing plugs must be removed. When the sealing plug engaged with the outlet is removed or unsealed, the pressurized lubricant can be discharged due to internal pressure. It may be desirable to remove the inert gas pressure through the inlet which is not directly connected to the discharge chamber. However, removal of the sealing plug engaged in the inlet does not allow the inert gas to be discharged because of presence of the check valve. Namely, because of high internal pressure, the check valve is held in the closed position so as not to permit the pressurized inert gas from being discharged through the inlet.